Minnesota's Lake Ice-Out Status - May 16, 2009

The definition of lake ice-out varies from lake to lake, and individual to individual. For some,
ice-out occurs only when the lake is completely free of ice. For others, ice-out is defined as
the moment when navigation is possible from point A to point B. And yet for others, ice-out is when
90 percent of the lake is ice free. Due to the variable definitions of this rather subjective
observation, the State Climatology Office attempts to contact the same individuals each
year to maintain a consistent record. The table below will depict 2009 information obtained from
this informal poll. The table is updated as conditions warrant.

Despite having substantial ice cover during the winter of 2008-09, the strong winds, warm temperatures and rain during the third of March hastened ice melt. By the end of March, the ice out line had reached the south edge of the Twin Cities Metropolitan area. Cooling temperatures for the last week of March and the first ten days of April slowed ice out progress considerably. Many of the medium-sized lakes have lost their ice in the Twin Cities Metropolitan area by April 8. By April 13, both White Bear Lake and Minnetonka had lost their ice.

The ice out line continued to inch northward with warmer temperatures from April 14 to 17. Lake Traverse had just a little ice left by noon on April 17 near Browns Valley. The average ice out for Lake Traverse is April 9.

By April 21, the ice out line for small and medium sized lakes had crept northward into the Alexandria area eastward to Mille Lacs. Mille Lacs still has substantial ice on it. In fact, the ice on Mille Lacs has been on the move the past few days. With a stiff north wind on April 19th and 20th, ice piled up on the south shore of Mille Lacs. The Mille Lacs Messenger has a video of the ice pile up. On April 23, strong south winds shoved the ice on Mille Lacs northward. The warm and windy conditions on April 23rd and 24th caused many lakes shed their ice in central Minnesota including Otter Tail and Mille Lacs

By May 4th, the ice remaining on lakes had retreated to mainly the far northeastern tip of Minnesota, and some of the larger border lakes with Canada. In general, lakes still had ice on them in Cook County, especially east of Saganaga in the Boundary Waters. Lake of the Woods still had substantial ice on it, with open water in some of the bays.

On Friday, May 8th there was still ice on Devil Track, Greenwood and Brule lakes in far northeast Minnesota.

As of the afternoon on May 11, only a few lakes including Greenwood Lake and Trout Lake in northeast Minnesota seem still have ice on them. On Saturday, May 16 Greenwood Lake was reported to be 95% ice free and thus was the last lake to be ice free in Minnesota.

See the May 10 high resolution polar orbiting satellite image for a great snapshot of lakes that were ice covered on that date for northern Minnesota.